LoginFragment.kt

class LoginFragment : Fragment(), Injectable {

    @Inject
    @VisibleForTesting
    lateinit var viewModelFactory: ViewModelProvider.Factory

    private lateinit var dataBinding: LoginFragmentBinding

    private lateinit var viewModel: LoginViewModel

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)

        viewModel = ViewModelProviders.of(this, viewModelFactory)
                .get(LoginViewModel::class.java)
    }

    override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?,
                              savedInstanceState: Bundle?): View? {
        val rootView = inflater.inflate(R.layout.fragment_login, container, false)
        dataBinding = LoginFragmentBinding.bind(rootView)
        dataBinding.viewModel = viewModel
        return dataBinding.root
    }

    override fun onActivityCreated(savedInstanceState: Bundle?) {
        super.onActivityCreated(savedInstanceState)

        viewModel.navigateToForgotPasswordPage.observe(this, Observer {
            startBrowser(Urls.FORGOT_PASSWORD)
        })

        viewModel.showErrorToast.observe(this, Observer {
            showToast("Error signing in.")
        })

        viewModel.navigateToNextScreen.observe(this, Observer {
            startHomeActivity()
            activity.finish()
        })
    }

    private fun startHomeActivity() {
        startActivity(Intent(activity, HomeActivity::class.java))
    }
}